/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.query.reader.universal;

import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.read.TimeValuePair;
import org.apache.iotdb.tsfile.read.reader.IPointReader;
import org.apache.iotdb.tsfile.utils.TsPrimitiveType;

import java.io.IOException;

public class FakedSeriesReader implements IPointReader {

    private int index;
    private int size;
    private boolean initWithTimeList;
    private static final TSDataType DATA_TYPE = TSDataType.INT64;

    // init with time list and value
    private long[] timestamps;
    private long value;

    // init with startTime, size, interval and modValue
    private long startTime;
    private int interval;
    private int modValue;

    public FakedSeriesReader(long[] timestamps, long value) {
        this.initWithTimeList = true;
        this.index = 0;
        this.size = timestamps.length;
        this.timestamps = timestamps;
        this.value = value;
    }

    public FakedSeriesReader(long startTime, int size, int interval, int modValue) {
        this.initWithTimeList = false;
        this.index = 0;
        this.size = size;
        this.startTime = startTime;
        this.interval = interval;
        this.modValue = modValue;
    }

    @Override
    public boolean hasNextTimeValuePair() {
        return index < size;
    }

    @Override
    public TimeValuePair nextTimeValuePair() {
        if (initWithTimeList) {
            return new TimeValuePair(timestamps[index++], TsPrimitiveType.getByType(DATA_TYPE, value));
        } else {
            long time = startTime;
            startTime += interval;
            index++;
            return new TimeValuePair(time, TsPrimitiveType.getByType(TSDataType.INT64, time % modValue));
        }
    }

    @Override
    public TimeValuePair currentTimeValuePair() throws IOException {
        throw new IOException("current() in FakedPrioritySeriesReader is an empty method.");
    }

    @Override
    public void close() {
    }
}
